1. Field of the Invention
The present invention relates to an automatic casting process of a continuous casting machine in which a flow rate of molten metal discharged from a metallurgical vessel into a continuous casting mold is controlled using a stopper end provided in the metallurgical vessel. During an initial casting mold filling mode, the stopper is repeatedly opened and closed according to preprogrammed time intervals and preprogrammed stopper positions to thereby discharge the molten metal into the continuous casting mold having an extracting end thereof sealed by a starting head.
2. Description of the Related Art
Conventionally, when the continuous casting mold is initially filled with molten metal, the mold is continuously filled with the molten metal, and during a specific dwell time, the molten metal sets and binds with a starting head which seals an extracting end of the continuous casting mold.
Upon expiration of the specific dwell time, which is established based on experience, the starting head is removed without consideration as to whether the molten metal has set, and a continuous casting passage is thereby produced.
According to the aforementioned process (Regelungstechnische Praxis and Prozessrechnertechnik, Issue 2, 1969, p. 68), automatic casting is targeted in that the stopper is actuated to "open" and "shut" positions using a control system responsive to a predetermined timing program. As the level of the molten metal within the continuous casting mold reaches the beginning of the measuring range of a level indicator arranged in the upper region of the casting mold, a limit indicator switches off the open/shut control, and a process for regulating this discharge amount of the molten metal is initiated so as to maintain a constant predetermined level of molten metal within the casting mold. In practice, it has been demonstrated that automatic casting using a stopper as the molten metal flow control element is extremely difficult to carry out due to its regulating characteristics. The regulation of the molten metal discharge amount cannot be finely adjusted using the stopper, since the stopper defines only a relatively short stroke from closing to a fully open position.